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Error messages of Websense Content Gateway are vulnerable to Cross-Site
Scripting
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Han Sahin, September 2014

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Abstract
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It was discovered that the error messages of Websense Content Gateway
process user-controllable data insecurely, rendering these pages
vulnerable to Cross-Site Scripting. Cross-Site Scripting allows an
attacker to perform a wide variety of actions, such as stealing the
victim's session token or login credentials, performing arbitrary
actions on the victim's behalf, and logging their keystrokes.

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Tested versions
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This issue was discovered on Websense Triton v7.8.3 and Websense
appliance modules V-Series v7.7. Other versions may be affected as well.

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Fix
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This issue is resolved in TRITON APX Version 8.0. More information about
the fixed can be found at the following location:
http://www.websense.com/support/article/kbarticle/Vulnerabilities-resolved-in-TRITON-APX-Version-8-0

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Details
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https://www.securify.nl/advisory/SFY20140916/error_messages_of_websense_content_gateway_are_vulnerable_to_cross_site_scripting.html


An example of a vulnerable URL parameter is the admin_msg parameter. The value of this parameter is a Base64 encoded error message. It is possible to include HTML and scripting code in the message, which is used as-is in the resulting error page. An attacker can construct a specially crafted HTML response, that must be encoded using Base64 and appended to the following URL:

https://<target>:8081/configure/ssl_ui/eva-config/client-cert-import_wsoem.html?admin_msg=<payload>

An attacker must trick victims into opening the attacker's specially crafted link. This is for example possible by sending a victim a link in an email or instant message. Once a victim opens the specially crafted link, arbitrary client-side scripting code will be executed in the victim's browser. The attacker-supplied code can perform a wide variety of actions, such as stealing the victim's session tokens or login credentials, performing arbitrary actions on their behalf, logging their keystrokes.